1. Field of the Invention
The present invention relates to a condenser which performs heat exchange between cooling water and a refrigerant, condensing and liquifying the refrigerant, and to a freezer comprising the condenser.
2. Description of the Related Art
In a large-scale structure such as a building, cooling water, which has been cooled in a freezer, is fed back through the structure along interconnecting pipes provided therein, and rooms are cooled by heat exchange of the cooling water with the air in the rooms.
FIG. 6 shows one example of a cooler which is installed in a freezer. The cooler has a plurality of heating pipes 2, alternatively provided and bundled, for feeding cooling water into a cylindrical receptacle 1, which a refrigerant is led into.
The thermal transmission pipes 2 are separated into inlet side pipes which connect to a cooling water entrance 3, and outlet side pipes which connect to a cooling water exit 4. A refrigerant entrance 5, which the refrigerant is led into, is provided in the upper section of the receptacle 1, and a refrigerant exit 6, which the refrigerant is led out from, is provided in the lower section of the receptacle 1.
The cooling water, which has flowed through the cooling water entrance 3, passes through the receptacle 1, turns in a water chamber (not shown), passes again through the receptacle 1 and is fed out from the cooling water exit 4. In this process, a hightemperature high-pressure gas refrigerant, which is led to the receptacle 1 from a compressor (not shown), is condensed and liquified by heat exchange with the cooling water. The cooling water takes the heat from the refrigerant, increases in temperature and is led out from the receptacle 1.
The evaporator of the structure as described above has problems such as the following. Although the refrigerant which is led into the receptacle 1 is condensed and liquified by heat exchange with the cooling water on the surfaces of the thermal transmission pipes 2, the refrigerant, which has been condensed and liquified in this way on the surfaces of the thermal transmission pipes 2 which are provided at comparatively high positions, falls in its liquified state toward the thermal transmission pipes 2 provided at lower positions, whereby much of the liquified refrigerant tends to adhere to the lower thermal transmission pipes 2, producing a thick liquid film.
Consequently, the thermal transmittancy of the lower thermal transmission pipes 2 decreases, making it difficult to perform heat exchange with a gas refrigerant which has not yet been condensed. As a result, the capability of the condenser is inadequate.
The present invention has been realized in consideration of the problems as described above, and aims to increase the thermal transmittancy in the condenser, and thereby provide a freezer having high cooling efficiency.
A condenser and a freezer having the following constitutions are used in order to achieve the above objects. A first aspect of the present invention provides a condenser for condensing and liquifying a refrigerant by inducing the refrigerant into a receptacle, in which cooling water is fed to through a plurality of thermal transmission pipes which are arranged in bundles. A plate body is provided between the bundles of the thermal transmission pipes, and slopes diagonally downward when viewed in cross-section from the direction of the length of the thermal transmission pipes.
In this condenser, the refrigerant which falls toward thermal transmission pipes provided at low positions is fed diagonally downward by the plate body, preventing the liquid film of the refrigerant which adheres to the surfaces of the thermal transmission pipes provided at low positions from becoming too thick. As a consequence, it is possible to prevent reduction in the thermal transmittancy of the thermal transmission pipes.
Further, the flow of the vaporized refrigerant is repelled by the plate body, driving it upwards against the thermal transmission pipes which are adjacently located above the plate body, thereby helping to remove the liquid film. This makes it possible to prevent reduction in the thermal transmittancy of the thermal transmission pipes.
According to a second aspect of the present invention, in the condenser of the first aspect, a plurality of the plate bodies are provided at the upper and lower sides with gaps therebetween.
In this condenser, the function of each of the plate bodies is the same as in the first aspect, but in a large-scale condenser having an extremely large number of thermal transmission pipes, the refrigerant can be exhausted effectively from the groups of pipes by providing the plurality of plate bodies between the thermal transmission pipes.
According to a third aspect of the present invention, in the condenser of the first aspect, a plurality of plate bodies sloping in different angles and directions are combined, and form a chevron-shape which projects upwardly when viewed in cross-section from the direction of the length of the thermal transmission pipes.
In the case of the large-scale condenser as described above, when the plate bodies are sloping in one direction, the refrigerant accumulates in one place inside the receptacle, whereby the drainage of the refrigerant from the receptacle does not progress smoothly. Accordingly, in this condenser, the refrigerant falling toward the thermal transmission pipes provided at low positions is caught and fed in two different directions. Consequently, the refrigerant does not accumulate in one place and there is no deterioration in the drainage of the refrigerant from the receptacle. Incidentally, the chevron-shaped plate bodies may be comprised by joining two plate bodies together, or by using a plate body which is already chevron-shaped.
According to a fourth aspect of the present invention, in the condenser of the third aspect, a plurality of the plate bodies forming the chevron-shape are provided with gaps therebetween.
In this condenser, the function of each of the individual plate bodies is the same as in the third aspect, but in a large-scale condenser having an extremely large number of thermal transmission pipes, the refrigerant can be exhausted effectively from the groups of pipes by providing the plurality of chevron-shaped plate bodies between the thermal transmission pipes.
According to a fifth aspect of the present invention, in the aforementioned condenser, the angle of the plate body (bodies) with the horizontal is set between 0 degrees and 60 degrees, and is preferably set between 3 degrees and 10 degrees.
When the angle of the plate bodies with the horizontal is too steep, the refrigerant falling to the lower thermal transmission pipes increases as in conventional condensers; when the angle is too gentle, the flow of the refrigerant becomes poor, making it difficult to exhaust the refrigerant from the groups of pipes. In this condenser, the angle is set between 0 degrees and 60 degrees, and is preferably set between 3 degrees and 10 degrees, making it possible to stop the liquified refrigerant falling toward the thermal transmission pipes which are provided at comparatively low positions, while enabling the refrigerant to be exhausted effectively from the groups of pipes.
A freezer according to a sixth aspect of this invention comprises the condenser of the present invention as described above, an expansion valve which decompresses a liquified refrigerant, an evaporator which evaporates and vaporizes the decompressed refrigerant, and a compressor which compresses the vaporized refrigerant and supplies it to the condenser.
In this freezer, the thermal transmittancy of the thermal transmission pipes in the condenser is increased as described above, resulting in an increased heat exchange rate. Therefore, the same capability as a conventional condenser can be achieved even when energy consumption is reduced.